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D33.4 ICD-10-CM Code: Benign neoplasm of spinal cord

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FY 2026 Apr update / Neoplasms (C00-D49) / Benign neoplasms, except benign neuroendocrine tumors (D10-D36)

D33.4

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Benign neoplasm of spinal cord

A non-cancerous tumor that grows within or on the spinal cord itself.

Buddy the Bee presenting code insight

Buddy Insight

Benign neoplasm of the spinal cord represents intramedullary tumors, most commonly ependymomas and astrocytomas, that arise within the spinal cord parenchyma itself.

CMS-HCC V28

HCC 23

RAF 0.251

CMS-HCC V24

HCC 12

RAF 0.150

ACA/HHS

0

0

RAF 0

ESRD/PACE

HCC 12

RAF 0.0

RXHCC

HCC 22

RAF 0.0

Code Trumping

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Code Book Path

Official
D33Benign neoplasm of brain and other parts of central nervous system
D33.4Benign neoplasm of spinal cord

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for D33.4 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D33.4 in this effective period.

Related Child Codes

Official
D33.0Benign neoplasm of brain, supratentorial
D33.1Benign neoplasm of brain, infratentorial
D33.2Benign neoplasm of brain, unspecified
D33.3Benign neoplasm of cranial nerves
D33.7Benign neoplasm of other specified parts of central nervous system

Includes

Official

ICD-10-CM does not list Includes notes for D33.4 in this effective period.

Excludes 1

Official
  • angioma (D18.0-)
  • benign neoplasm of meninges (D32.-)
  • benign neoplasm of peripheral nerves and autonomic nervous system (D36.1-)
  • hemangioma (D18.0-)
  • neurofibromatosis (Q85.0-)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D33.4 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for D33.4 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for D33.4 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
MRI of the spine documenting an intramedullary lesion is required.
Specify the spinal level (cervical, thoracic, lumbar, conus medullaris), tumor dimensions, and any associated syringomyelia.
Pathology from biopsy or resection should confirm benign WHO grade.
Document neurological examination findings, functional status, and treatment plan.

MEAT Support

HCC Buddy guidance
MRI of the spine documenting an intramedullary lesion is required.
Specify the spinal level (cervical, thoracic, lumbar, conus medullaris), tumor dimensions, and any associated syringomyelia.
Pathology from biopsy or resection should confirm benign WHO grade.
Document neurological examination findings, functional status, and treatment plan.

Audit Caution

HCC Buddy guidance
The critical distinction is intramedullary (within the cord, D33.4) versus intradural-extramedullary (meninges, D32.1 or nerve root, D36.1). Cauda equina tumors below the conus are not spinal cord tumors and should not be coded here. Confirm benign status with pathology
spinal cord ependymomas can be WHO Grade II or III.

Common Mistakes

HCC Buddy guidance
D32.1 (benign neoplasm of spinal meninges) is for intradural-extramedullary tumors, not intramedullary
D33.3 (cranial nerves) is for intracranial nerve tumors
D36.10 (peripheral nerve neoplasm) is for tumors of spinal nerve roots outside the cord
D43.4 (spinal cord, uncertain behavior) is for tumors with indeterminate biology.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is D33.4 an HCC code?

Yes. D33.4 maps to Melanoma and Other Skin Cancers under the CMS-HCC V28 risk adjustment model (and Breast, Prostate, and Other Cancers and Tumors under V24).

HCC Category Mapping

V28HCC 23, Melanoma and Other Skin Cancers
0.251
V24HCC 12, Breast, Prostate, and Other Cancers and Tumors
0.150
ESRDHCC 12, Breast, Prostate, and Other Cancers and Tumors
0.000
RxHCCHCC 22, Cancer, Other Specified Sites
0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for D33.4

For D33.4to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

  • MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
  • EEvaluate: test results, medication response, or physical findings reviewed by the provider
  • AAssess: explicit mention in the assessment or plan with acknowledgment of status
  • TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed D33.4 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

D33.4 is the ICD-10-CM diagnosis code for benign neoplasm of spinal cord. A non-cancerous tumor that grows within or on the spinal cord itself. D33.4 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering benign neoplasms, except benign neuroendocrine tumors (d10-d36).

Under the CMS-HCC V28 risk adjustment model, D33.4 maps to Melanoma and Other Skin Cancers (HCC 23) with a community, non-dual, aged base RAF weight of 0.251. Under the older CMS-HCC V24 model, D33.4 maps to Breast, Prostate, and Other Cancers and Tumors (HCC 12) with a community, non-dual, aged base RAF weight of 0.150. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Distinguish between spinal cord tumors (D33.4) and spinal meningeal tumors (D32.1). Because D33.4 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for D33.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Distinguish between spinal cord tumors (D33.4) and spinal meningeal tumors (D32.1)
  • Document the level of spinal cord involvement (cervical, thoracic, lumbar) for comprehensive clinical documentation

Clinical Significance

Benign neoplasm of the spinal cord represents intramedullary tumors, most commonly ependymomas and astrocytomas, that arise within the spinal cord parenchyma itself. These tumors can cause progressive myelopathy, sensory loss, weakness, and bowel/bladder dysfunction. Despite their benign histology, surgical resection can be challenging due to the eloquent nature of the spinal cord tissue.

Documentation Requirements

  • MRI of the spine documenting an intramedullary lesion is required.
  • Specify the spinal level (cervical, thoracic, lumbar, conus medullaris), tumor dimensions, and any associated syringomyelia.
  • Pathology from biopsy or resection should confirm benign WHO grade.
  • Document neurological examination findings, functional status, and treatment plan.

Commonly Confused Codes

  • D32.1 (benign neoplasm of spinal meninges) is for intradural-extramedullary tumors, not intramedullary
  • D33.3 (cranial nerves) is for intracranial nerve tumors
  • D36.10 (peripheral nerve neoplasm) is for tumors of spinal nerve roots outside the cord
  • D43.4 (spinal cord, uncertain behavior) is for tumors with indeterminate biology.

Child Codes

Code Hierarchy

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